Method of and apparatus for cooling liquids, confections, and the like



Feb. 10, 1948. A, F McMAHON 2,435,942

.METHOD OF AND APPARATUS FOR COOLING LIQUIDS CONFECTIONS,. ANO THE LIKE Fil ed Dec. 15, 1945 3 Sheets-Sheet l IN VEN TOR.

Feb. 10, 1948. A. F. MCMAHON 2,435,942

METHOD OF AND APPARATUKFOR COOLING LIQUIDS, CONFECTIONS, AND THE LIKE Filed Dec. 15, 1945 s Sheets-Sheet 2 I l QOQQQQQ 4 glad/20W Feb. 10, 1948. A. F. MQMAHON 2,435,942

METHOD OF AND APPARATUS FOR COOLING LIQUIDS, CONFECTIONS, AND THE LIKE Filed Dec. 15, 1943 3 Sheets-Sheet 3 INVENTOR.

Patented Feb. 10, 1948 UNITED J STATES PAT E'N'l'. OF F 1 CE METHOD OFKNDAPPARA'TUS FOR) COOLING LIQUIDS, CONFEGTIONS; AND THE LIKE Alexander "F M cMahon, Oak Park, IilL, assignor to The Bastian-Blessing Company, Chicago, 111., a corporation of Illinois Application December 13, 1943; serial No;514,120

14 Claims. I

This invention relates'to the method of and apparatus for cooling water, and especially for simultaneously cooling sweetand carbonated water, and -a=compartment containing jars of extracts, and the like -in conventional sodaffountain cabinets; and like constructions.

One of the objects of the invention is theprovision ota cooling unitso constructed that,- aside fromthe'compressor and condenser, it is a selfthe'main refrigerating system-arid the unit may be-easily' and readily replaced with a; similar unit in 7 Working condition,- either 'for permanent use or forluse temporarily while repairs are being made.

A- further object of the invention is to provide aclosed or selfcontaining' body' of refrigerantas an intermediate heat transfer element between a refrigerant" cycled'thi'ougha' liquifier and a freezable liquid, such as water, which is to be cooled without being frozen.

Another object oi the invention is-the provisio'rr oia cooling unit having a cycle of operation m-wmen the-conversion of the refrigerant workme directly upon a water coil is: effected without the'aidoi pumps or similar mechanical means imam improved and seli contained manner.

"Astill furtherpbje'ct of the-invention is the provision ref anew and improved'method'of cooling; potable iiquids and the like, efiiciently and expeditiously I and "with the cooling action cuhioned byran intermediate 'body of: refrigerant which; protects the "main' body of refrigerant against contamination, and the liquids against freezing.

Another object of the invention isthe provi sioii'of new and-improved mechanism so-constructed that the valves employed in the cooling mechanism-ioperate with prompt: 'or snap action.

'A-iurther: object of the inventionisthe:- provision of a' hermetically sealed; cooling unit that is simple in construction, efficient in operation, composed of fewmoving parts,- that is easily assembled, and that: is automatic in operation Other and further objects and advantageso! the invention will appear from the iollowingrde scriptiom taken in connection with theaccompanyingdrawings in which- Fig. 1- is a perspective view of a soda fountain cabinet containing the invention;

Fig. 2 is -a side' elevation of the refrigerating cabinet shown in Fig. 1 with parts in section" and parts broken away and the respective-elements grammatically:

Fig.3 is avertical section of the cooling unit removed from the cabinet, shown: on an enlarged scale, with parts brokenaway and shown-more or less diagrammatically;

Fig; a is a vertical" section of the cooling-unit, but-showing a slightly modified iorm (it-construction;

Fig. 5 is a vertical section of the float control valve and associated. parts,"with parts broken awayyand Fig. 6 is an elevation of the-valve mechanism I11 soda fountains, Cbihtfi, dblifitis, '01 "C611- fection dispensing apparatus, it is desirable 1 that means he provided for maintaining the interior of the cabinetat a reduced temperature for keeping the various syrups, eXtracts'and-daiiy products'stored therein at a desired low't'em perature, and at the same time provides. 'mechanism for instantaneously, or' at least rapidly,

' cooling's'we'et and'carbonated'water that may "be.

conductedthrough the cabinet to thedispen'smg apparatus 'at the counter.

It is extremely important in iountainsservliig the public that'tl'ie water, whether sweet sitar-- and their arrangement shownmoreor =less diapensing type, and comprises an upper section I1;

Fig. 2, having the syrup and extract jars 18 therein and the dispensing or draft arms 19, 2|,

and 22, as is usual in such constructions. These draft arms are provided with the' usual valves The arms l9 and '22 contain the 23, 24 and 25.

conduits for carbonated water, and the arm 21"" carries a conduit for the sweet water. Since the detailed construction of the soda fountain cabinet itself constitutes no part of the present invention, it is not thought necessary to further illustrate or describe the same except to say that. the cabinet may be supported on the floor 2E, and thecompressor, condenser-and carbonator may be mounted in a space below, as, for-instance,

uponthe cement floor 2'l of a basement. The carbonator is indicated" at 16 and'since it constitutes no partof the present invention it is not thought necessary to-illustrate ordescribe the same further in detail. I

-The'cabinet is divided into a series of compartments each having a closure 28. The cooling unit- I2 is mounted in one of the compartments through which-the sweet and carbonated water is conducted,- The remaining. compartments may be provided with expansion coils which are so' constructed and arranged that certain of the compartments will beheld ata lower.temperature than others, as is usual in such construe-- tions. V I

The cooling unit I 2 is mounted within the cabinet H, Fig. 2, and may be mounted in. any portionof tbecabinet Where other than temperatures below-32 F. exist. As shown, it is mounted on the floor of the cabinet at the end supporting the dispensing arms I9, 2| and 22 It maybe secured to the floor of the cabinet in any suitable manner, asibyfthe legs29. Fig. 3, having their lower ends secured to the floor of the compartment; by bolts 3 I, .or the like.- Although the cooling unit may be provided in any form in which a secondary and closed body of refrigerant has its liquid portions in contact with the water coil and its vapor. portions in controlled heat exchange relationship with a refrigerating coil, it is preferred to provide a construction comprising a cooling or lower chamber 32, a reservoir, intermediate or float chamber 33, and an upper or. condensing chamber 34. Two forms of this gen-.

eral arrangement are shown.

The float'chamber is supported from the coolin '.chamber by suitable supports, such as the arms 35, in an appropriate manner, as by being welded to the top of the lower chamber and to thebottom of the intermediate chamber. The

cooling'chamber 32 is preferably, but not neces'-.

sarily, "of sheet metal, and comprises a lower section36 which'may be circular and depressed at its-central portion, asat 31, and having a flange 38' extending around its periphery. An upper inverted cup-shaped section '39, havin its' lower edge flanged, as at 4!, is adapted to register with the flange 38 and be welded thereto, thus forming a closed" air-tight chamber, Mounted Within the' 'chamb'er are a pair of cooling coils 42, 43,- forming a part of the conduit for conductingsweet and carbonated water, respectively. to the dispensing arms of the fountain. Only the water coil 42 would be provided in case of use of the invention with a drinking fountain.

The cooling chamber 32 is adapted to be filled with refrigerant 40, such as Freon (F-l2) to a level above the coils. The sweet water pipe 42 is connected with any suitable source of water supply, and its other end is connected with the dispensing valve 24. The cooling coil 43 is connected to the carbonator l6, and its opposite end is provided with a branch pipe 44 connected to the valves 23 and 25.

The upper or condensing chamber 34 is pref- .erably above the cooling chamber 32, and comprises" a lower'cupqike section 45, having its upper peripheral edge turned outwardly to form the annular flange 46 and an upper closure section 41, having a, peripheral flange 48, rigidly secured to the flange 46 as by being welded thereto. When" either sweet or carbonated water is conducted through the'coils' 42 or 43 there is an= exchange of heat between the waters in these coils and the refrigerant 49, so that the refrig erant is caused to boil and the vapor is conducted to the upper chambe 34 through a suitable passage '49;

Although the vaporcan be recondensedby" being brought into contact with a refrigerating coil where flow of refrigerant therethrough is controlled, it is preferred to also control the flow ofthe vapor by a pressure responsive relief valve which J maintains a controlled pressure in the lower chamber and in combination with a recondensing coil a partial vacuum in the upper chamher. For this latterarrangement the passageway 49 includes a pressure control valve 5| in its lower portion, This valve has its'valve cham-' ber 52 connected to an elbow conduit 53, secured in the upper end of the cooling chamber 32 so as to conduct the refrigerant vapor therefrom into the valve chamber 52. This valve chamber has in its lower portion a valve seat 54, on which a ball valve 55 is adaptedto engage. The valve seat is of less diameter than the ball valve. so that a predetermined pressure of the vapor on the valve will unseat the same after it has been released, and permit the vapor to pass out through the valve opening into the conduit 49, and from the conduit 49 into the condensing.

chamber 34 in which the upper end of the con-1 duit 49 is secured.

The valve 55 is supported by a valve cage 56, whichguid'es the movement of the valve and holds it in closed position, and this cage is adapted to be raised for releasing the valve.. The valve cage 56 is movable vertically, and is provided with a metal bellows 51, which is normally extended for resiliently holding the ball valve on its seat. Th resiliency of the bellows is such that when the pressure of the refrigerant vapor within the cooling chamber32 reaches an amount slightly in excess of the springresistance of the bellows, the metal bellows 51 will be forced upwardly, carrying with it the valve cage 56and ball 55, sothat the vapor pressure, reacting on the bellows 51, will elevate the ball 55 and permit vapor to pass outwardly into the conduit 49, as described above.

Mounted within the upper or condensing cham-' ber 34'is an expansion coil 59, which in turn is in communication with an expansion valve 6| of the usual construction. A suitable thermostat 62, which is responsive to the temperature of the" refrigerant gas passing back to the compressor throughzthesconduit fi3 vcontrols; thezoperationof the: valve 6 t01:admittingrrefrigerant tathe 'ex pansion coilifl. Since the construction of t'he expansion nzcoilvand thermostatxcontroi for the same; are :ofithe 1 usualaor any well knownrcon struction; sit .is nctrthought necessary.'to..describe the same.

:Thezli'quid; refrigerant: from: t-hetcondenserz l; Fig. :2; isconducted' to: the, valve 8| by the conduit 64. The expansion coil 59 may bewprovidedwith a plurality .of: heat. radiating discs: 65". for more readily eflectingaa heat 7 exchange between the reiTrigera-nt :vapor: introduced "through the .conduit M ami" the refrigerant in: the co'il ES. .This

refrigerantobeing atifa, low .temperatureiabsorbs' heatrrom the pipe andfins; thus cooling: them; whichin turn condenses the vapor of the reiriger ant "entering? through" the "conduit 49, and the condensed refrigerant falls to the bottom of the container, as 91, 40?" :The' rair'withinifthe :difierent chambers of the cooling unit 12 is: "preferably evacuated I or re= moved; so that the: refrigerant vaporentering the condenser through thepassage 49 and condensing on the coilEQ and radiating discs lit-will maintain a partial vacuum in thescondensing chamber 34, while, on the ;other. :hand; thel'evaporation of the refrigerant :40: in the: cooling chamber 32 will maintaina pressure abovethe-atmosphere within the lower chamber. Sincethe air has-been previously exhausted, this highv pressure inthe evaporating. chamber v32Wi11, when it reaches a predetermined amount, compressthemetal bellows 51 and open the valve 55, :and: the pressure oi'ithe refrigerant vaporin the lower chamber will force this vapor upwardly into the condensing chamber 34. Suitable means are provided ior conducting the condensed liquid refrigerant at 46% back to the cooling chamber -32. Sincethepressure within thechamber 34 is 1 farzbelowthat within the chamber 32, and: since, pressurev is. continuously being developed. withinithe chamber 32,. an additional chamber withv suitable valve and control mechanism, is provided 'for transierringthe condensed refrigerant irom the condensing chamber 34- to the evaporating chambera32i As shown by wayl of illustration, the -interme-' diatezchamber -33 is cup-shape in iorm, and has its upper. edge for-med outwardly to form a seat for:receivingithe-lower endof the upper or condensing chamben to which itis rigidly secured, as by being welded thereto; Thebottom wall ofthe 'condensingl chamber- I2 is; provided with a conduit 66 for conducting thgliquidrefrigerant air lll down" to the valve mechanism fi'l, mounted on the bottom -wa-llxof' the intermediate section 33. Thisvalve mechanism comprisesa standard 68, 5, the lower end of Which-is. screwthreaded, as at 69,and adapted to extend'through the bottom Wall of theflintermediate-section 33. It is a secured thereto lby aiclamping nut "1|", adapted to clamp, the parts .in'position. to. form a liquid-tight ,joint. Suitable vgaskets "[13, are adapted to'be inserted between the bottom wallof the intermediate, section 33 and anannular shoulder Ml'fo'rme'd on the standard168, and'between the wall-33landclamping nutllj. The upper end of thestandardIGB is provided with a' passage 15, the outer end of whichiis enlargedand'within whichthe lower end of. the conduit 66 issecured;

The standard Ellis, rovided with a lateralextension 16;" having a passage 11 extending down wardly within the same and intersecting'thepas sage 15.. The upper end of the passagellforms a valva'seat for: avalve18, whichwiscarrled 'by anannularor ring-dike valve-supporting'member 19,: Fig. 6. :The vertical .diameter of' the valvesupporting member "I9 is larger. than the vertical diameter ofiTthe extension 16, so that when the member 19' is at its'upper limit of movement the valve 'TBiWill' bezopened and permit the liquid refrigerant: at lfl 'to pass out through the valve opening intothe-intermediate ofifloat chamber 33, as will presently be described. A valve stemfll is secured to the. lower end oftheannular membe!" 19; and extends downwardly through a guide arm's-82. and through avalve opening or passage 83, and terminates inavalve 84 which is adapted toengage a valveseat 'eat the 'lowerend' of the passage 83,

The lower end of the thread portion 69' of the standard 681is provided with a recess orcounterlacro se-withinwhich the'valve 84 is positioned. The lower threaded'endxof the. projection 69' is adaptedtobe engagedbyia pipe couplingrafi, to which is attached a conduit 8'1, the lower end of which extendsthrough the upper wall of thecooling or evaporating chamber'tzrand is secured therein. .Thevalves I8 and'84' are'interconnected in such manner thatrwhen one is closed the other isiopen.

suitable means are provided for automatically controlling the operation of the valves!!! and 84: Afioat'ts is employed for this purpose; The float 88, having an attaching arm 89, is pivotedy-asatflL on the standard68. 'Iheinner end of the'arm' 89'is bifurcated, and the inroations 92 extend at opposite sides of 'the valve stemlflL-as shownin Figs; 5 andfi. When the float 88 is lowered theiurcations 92 will engage the ring member 19 and raise the valves so that the valve-l8 will be opened for permitting the refrigerant x at M to new down into the float chamber 33, and simultaneously the valve 84 will be closed, thus preventingthehigh pressure refrigerant gas from passing up from the cooling chamber 32 into the middle'chaniber 33.

The'valve stem- 8! is provided below the furcati'ons 92 with' a stop or shoulder 93, so that when thefio'at 88 is elevated byincreasing the amount of liquid in the float chamber 33 the furcations'will engage the'stop or shoulder'93, close the valve 18, and openthe valve 84 for permitting the liquid to pass from the float 'chambar to the cooling chamber'32. Themembe'rlfi and the stop or shoulder 93 arespaced apart to permit considerable movement of the lever and float before operating the valve. In other words, the-valves lll andfl are not operated until the floatnears the limit of its movement in either direction. The parts are so constructed that the two-valves-move together with a snap action, as will now be described.

Assuming-now that the parts are'inthe position-shown in Fig; 5, with the valve 84' open and the valve lfl closed. The pressures in thelnter medi'ateand lowerchambers will firstequalize. The'pressure'in the upper chamber then becomes much less than that in the chambers 32 or 33, and consequently thisunequal pressure on opposite sides of the valve tends to firmly seat this valve. The pressures in the intermediate and lower'ohambers being equalized, the refrigerant liqnid'within the chamber33 flows into the lower chamber -32- and the float follows the level downwardly. When the float nears its downward movementihe furcations 92 engage'the ring member-I9 and tend to raise the valvelii. But since there is considerable more pressure now within the chamber 33 than in the chamber 34, the valve 18 will not open promptly when thefurcations 92 engage the ring member 19. Upon further'lowering of the liquid level in chamber 3 the weight of the float will finally overcome the pressure differential and the valve will be lifted to break this partial vacuum and open with a snap action under the combined movement of the float and additional pressure on the under side of this valve 18.

Assume, now, that the valve 84 is seated, the valve 18 is open, and the pressures in the chambers 33' and 34 are equalized through the open valve 18. The pressure in the lower chamber 32 will now be above the pressure in the intermediate chamber 33, and consequently the pressure on the lower side of thevalve 84 is greater than that on its upper side. The flow of liquid refrigerant from the upper chamber 34 continues, and as it continues the float rises higher and higher, and the furcations 92 finally contact the collar 93; but since the pressure is greater on the lower side of the valve 84 than on its upper side the valve is held against opening until the buoyancy of the float overcomes this difference in pressure. When the valve 84 is unseated it moves with a snap action because of the buoyancy' of the float and of the equalization of pressure on opposite sides of the valve 84. With the valve 84 open and the valve 18 closed, the parts are in position to repeat the cycle.

The cooling unit I2 not only cools the sweet and carbonated water conducted through the unit, but the unit itself absorbs heat from the chamber within which it is mounted, thus assisting in lowering the temperature of that chamber during rest'periods so that it assists in normallizing water temperatures during rush periods.

It will thus be seen that preferably there are two refrigerant systems, the first comprising the compressor IS, the condenser I5 and the expansion coil 59 for cooling the unit l2; and the second comprising the chambers 32, 33 and 34, together with the expansion coil 59, which constitutes a condenser, the float valve mechanism and the pressure valve 5| for cooling sweet and carbonated water.

The construction shown in Fig. 4 differs slightly from that just described, but since the parts are similar they are designated by the same reference characters with the addition of letter exponents, the position of the heads on the compartments being reversed. For instance, the sweet water and carbonated water coils 12 and 43 enter and leave through the sides of the compartment being built as a unit therewith instead of with the head. The water enters the upper opening and leaves the coil at the lower end,

In the construction shown in Fig. 4, the expansion coil 59 is not employed in connection with the cooling unit but is adapted to be used in connection with the type of refrigerating system in which the operation of the motor is more or less continuous with the expansion valve mounted independently of the unit l2 in another portion of the cabinet. In this form of construction the conduit 49* extends within the condensing chamber and its end is upwardly extended, as shown at 94, and may be provided with discharge openings below the end, as shown at 95.

The intermediate or float chamber 33 is smaller than the float chamber 33, so that the valve housing or casing 5| is located alongside this float chamber directly beneath the upper chamber 34*, and in this construction the supporting standards-35 are attached at their upper ends to the upper section 34 instead of to the intermediate section, as in Fig. 3. Various otherminor changes are present, as, for instance, the conduit 53* is provided with an air nozzle 10 for permitting the escape of entrapped air in the lower chamber, while charging the apparatus, a will presently appear.

Any suitable means may be provided for removing the air from the unit preparatory to itsoperation. Any suitable method or means may be employed for this purpose. In practice, the unit is inverted and the liquid refrigerant is introduced into the chamber 32 or 3'2 through a suitable conduit, as through the conduit 53 and nozzle 10, Fig, 4, or through any other port that may be provided.

After the chambers have been filled, that is, after the air within the chambers has been replaced by refrigerant, the unit is turned to normal upright position and, without permitting the entrance of air, the unit is purged of the excess refrigerant and sealed against the entrance of air or escape of refrigerant.

It is thought from the foregoing, taken in con-' nection with the accompanying drawings, that the construction and operation of my device will be apparent to those skilled in the art, and that changes in size, Shape, proportion or detail may be made without departing from the spirit and frigerant in said cooling chamber whereby heat extracted from the liquid passing through said coil will evaporate the liquid refrigerant in said cooling chamber in cooling said liquid, an expansion coil in the condensing chamber, a passage for conducting the refrigerant vapor from said cooling chamber to said condensing chamber, a pressure operated valvein said passage, means for maintaining said expansion coil ata low temperature for condensing said vapor, aconduit for conducting the condensate to said float chamber, a passage for conducting said condensate back to said cooling chamber, and means controlled by the height of said condensate in said float chamber for controllin the flow of said condensate to said cooling chamber.

2. In combination, a refrigerating circuit comprising a compressor, a condenser, an expansion coil in series with said compressor and condenser, a float chamber, a condensing chamber enclosing said expansion coil, a cooling chamber for containing a liquid refrigerant, a cooling coil extending into the refrigerant within said cooling- .3. Axcooling unit oomprising'a cooling chamberlfor containing ta liquid refrigerant, a conduit immersed fin'said refrigerant for conducting a liquid to be cooled through saidxrefrigerant for vaporizing said refrigerant for' cooling said liquid, means including a controli mechanism for conducting the refrigerant vapor from said chamber .to maintain: a predetermined temperature therein, means for condensing said vapor,

and means for returning the condensate to said cooling chamber.

4. A cooling unit comprising a condensing chamber, a refrigerant reservoir, a cooling chamber for containing a bodyof refrigerant; a conduit for conductingia potable-1iquid through said.

body for cooling said liquid by impartingitsheat to said liquid refrigerant thereby evaporating the refrigerant, a conduit for conducting the vapor of said refrigerant to said condensing chamber,

a pressure-controlled valve in said conduit, con

densing means in said condensing chamber, a conduit for conducting the condensed refrigerant from said condensing chamberto said reservoir, a conduit between said reservoir and said cooling chamber, valves for said conduits, and

float means for controlling the operation'of said 5. In a'water cooling unit, a cooling chamber for containinga liquid refrigerant, a condensing chamber, a reservoir, a cooling coil immersed in duits for conducting the condensed refrigerant.

from said condenser chamber to said reservoir and from said reservoir to said cooling chamber, and means for controlling the flow of condensed refrigerant through said conduits.

6. In a cooling unit, a cooling chamber for containing a refrigerant in liquid form, a cooling coil immersed in said liquid for conducting a liquid to be cooled through said refrigerant, a condensing chamber, means for conducting vaporized refrigerant from said cooling chamber including an automatic valve operative to maintain a predetermined temperature in the cooling chamber to said condensing chamber, means associated with said condenser chamber for condensing said vaporized refrigerant in said condensing chamber, and means including automatically operated mechanism for returning the condensed refrigerant to said cooling chamber to be recycled.

7. In a cooling unit, an upper chamber, a lower chamber below said upper chamber for containing a refrigerant in liquid form, an intermediate chamber, conduits between said upper and lower chambers, between said lower and intermediate chambers and between said upper and intermediate chambers, means for conducting a liquid to be cooled through the refrigerant in said lower chamber for cooling the liquid and for evaporating said refrigerant whereby the pressure of the vaporized refrigerant will cause the vapor to fl-ow upwardly into the upper chamber, an expansion coil within said upper chamber for condensing said vaporized refrigerant, pressure-controlled means for automatically controlling the flow of vaporized refrigerant from said lower to the upper chamber, and float controlled means for controlling the flow of ,condensed refrigerant from said upper to said intermediate chambers and from said intermediate tosaid lowerchamber for recycling.

8. In a cooling unit, a-coolingcha'mber, a condensing chamber,- .a cooling coil for conducting a liquid through saidcoolingchamber for cooling thesamaabody of refrigerant liquid insaid cooling chamber surrounding said coil, pressure- -controlled means for conducting refrigerant vapor from said cooling chamber to said condensing chamber, a heat exchanger in said'conliquids, said= lower chamber being adapted to contain a body of liquid refrigerant to be vaporized: by theliquids flowing through said'coils, means for conducting said vaporized refrigerant from'said lower to said upper chamber only when the vaporv pressure within? said lowerchambc'r rises above a predetermined amount, La heat Iexchanger withinltheupper' chamber for condensing said vaporized refrigerant, means including a float mechanism and a couple of valves for transferring the condensed refrigerant from said upper to said intermediate chamber when the level of the refrigerant liquid Within said intermediate chamber falls below a predetermined level, and means for transferring liquid refrigerant from said intermediate to said lower chamber when said float rises above a predetermined level.

10. A method of cooling a metallic chamber and simultaneously cooling water and Water containing dissolved carbon dioxide which comprises transferring heat units from the walls of said chamber and from said liquids to a refrigerant within said chamber whereby vapor in excess of that needed to maintain a predetermined pressure in that chamber is developed, conveying said heat units in the excess vapor to a second refrigerant in a second closed chamber, removing the second-named refrigerant with said units from said last-named chamber, and returning the firstnamed refrigerant in condensed form to the first-named chamber for recycling.

11. A cooling unit comprising a cooling chamber, a condensing chamber, and a float chamber, for containing a refrigerant in a closed circuit, in liquid and vapor form in each chamber, a cooling conduit adapted to be immersed in said liquid refrigerant in the cooling chamber for cooling the liquid, a passage for conducting vapor refrigerant from said cooling to said condensing chambers, a pressure-controlled valve for said passage, an expansion coil in said condensing chamber, a refrigerating unit for circulating a refrigerant through said expansion coil for condensing said refrigerant vapor, a passage for the condensed refrigerant from said condensing chamber to said float chamber, a conduit for conducting said condensed refrigerant from said float chamber to said cooling chamber, interconnected valves for said conduits, and a float within said float chamber for simultaneously opening one of said last-named valves and closing the other and vice versa, said chambers having a greater portion of the air evacuated therefrom 11 wherebysaid last-named valves open and close with a snap action.

12. A method of cooling a potable liquid including storing a body of refrigerant in a closed compartment in both its liquid and vapor phases,

it to reduce the pressure upon it below the pressure present in said compartment, and returning said condensed refrigerant to said compartment.

13. A method of cooling a potable liquid without freezing it comprising conducting a stream of the potable liquid into heat exchange contact with a body of liquid refrigerant without mixture therewith, transferring excess sensible heat from the potable liquid to the refrigerant to vaporize some of the refrigerant, withdrawing vaporized refrigerant to maintain a predetermined pressure and temperature upon the body of liquid refrigerant, chilling the withdrawn vaporized refrigerant to condense it and to reduce its pressure to a pressure below the pressure maintained on change relationship, but without mixture, with a body of liquid refrigerant confined under pressure to vaporize some of the liquid refrigerant and thereby remove heat units from said potable liquid, removing the vaporized refrigerant from said confined body of refrigerant to maintain the body of liquid at a predetermined temperature, confining and. liquefying the expanded vaporized refrigerant including the removal of said heat units carried thereby and the reduction of its pressure in its confinement and returning the liquefied refrigerant to said confined body of liquid refrigerant. ALEXANDER F. McMAHON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS v 5 Number Name Date 1,865,513 Gaugler July 5, 1932 2,182,997 Thomas Dec. 12, 1939 2,022,787 Smith Dec. 3, 1935 2,044,609 Hedlund June 16, 1936 2,022,764 Gibson Dec. 3, 1935 

